他就会装 翻译成英语

He can do nothing but play cool!
我想提醒一下 楼上的回答中出现好几个effected，其实应该是 affected，是矫揉造作的意思，比如 I am sick of his affected manners.（我讨厌死他那做作的嘴脸）

我理解的“装”是耍酷的意思 呵呵 不知道对不对

He will install

He only knows how to pretend.

He's so fake. （他很假）

1 he always in an effected way .
2. he puts on too many frills.

effected
puts on too many frills.

装腔作势